+ HBr!H = OH CH CH 2. HgOAc

Transcription

1 radical substitution Cl hv + Cl 2 + Cl! = Energy radical addition RR + electrophilic addition + C3 C3! = Energy Energy + 2 acetone water ! =! = Energy Energy acid catalyzed hydration + 2 +! = Energy C=C 2 C 2 oxymercuration - reduction (two steps) the first step + g(ac) 2 C=C 2 C C 2! =! = + Ac Energy Energy Energy hydroboration - oxidation (two steps) gac the first step + B 3 C=C 2 B 2 C C 2 Energy

2 ydration of Alkenes to Alcohols - Three General Methods Dr. Gergens - SD Mesa College I. Acid Catalyzed ydration w/ major limitation factor exposed: desired alcohol not produced C=C " -- S 4 complete the picture for these reaction intermediates! " C-C 2 carbocation " C-C 1,2 hydride shift carbocation rearrangement : migration C-C 3 carbocation C 2 - desired alcohol C 2-1 carbocation II. xymercuration-reduction (demercuration): "major limitation in acid-catalyzed hydration solved" " C=C g(ac) C-C -- C-C 2 NaB 4 C 2 - Ac ends on most mercurinum ion alkyl mercury acetate substituted carbon Markovnikov III. ydroboration-xidation anit-m C=C B 3 TF C C 2 2 C-C 2 2 C 2 -C 2 transition state alkyl borane *** Draw a reaction energy for each of these reactions

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4 mild ARS cold KMn 4 s cold cis T KMn 4 T KMn 4 1.MCPBA 2. +, 2 T KMn 4 trans MCPBA meta-chloroperoxybenzoic acid mild MCPBA Me 2 S epoxide Know mechanism for epoxidation Zn(s) Me 2 S Know mechanism for epoxide ring opening Synthesis of alkenens acidic condtions 1 Propose a synthesize for cyclohexene from cyclohexane basic condtions 2 Propose a syntheses for compounds 1,2, 3 shown on the right starting from cyclohexane 3 neutral condtions

5 A l k e n e R e a c t i o n s - G i v e P r o d u c t, N a m e & T y p e Gi v e l a b e l s, i d e n t i f y c o n d i t i o n s, c o m p l e t e b y g i v i n g t h e c o r r e c t p r o d u c t a n d n a m e e a c h r e a c t i o n. C o n d i t i o n s ( a c i d i c, b a s i c, n e u t r a l, o x i d i z i n g, r e d u c i n g, p o l a r p r o t i c, p o l a r a p r o t i c, n o n p o l a r, h v e t c. ) reaction name/type Cl 2 1.B 3 TF , 1.g(Ac) 2, 2 2.NaB 4 Cl RR hv 4

6 cold KMn 4 reaction name/type hot KMn Zn MCPBA Cl 2 1.MCPBA 2. 2, + cold KMn 4 hot KMn 4 5

7 a. Name the reaction and state the reaction. M e c h a n i s m s - A d d i t i o n R e a c t i o n s b. Give a stepwise mechanism for the following reaction. Your mechanism should show individual steps in the reaction that lead to all the products formed. Use curved arrows and indicate all formal charges. reaction name/type reaction name/type 2 + 6

8 M e c h a n i s m s - A d d i t i o n R e a c t i o n s a. Name the reaction and state the reaction. b. Give a stepwise mechanism for the following reaction. Your mechanism should show individual steps in the reaction that lead to all the products formed. Use curved arrows and indicate all formal charges. RR reaction name/type reaction name/type 1.MCPBA 2. 2, + 7

9 Complete the following reactions: A d d i t i o n R e a c t i o n s reaction name reaction name 2 Pt Zn hot KMn 4 reaction name 1.g(Ac) 2, 2 2.NaB 4 reaction name Complete the reactions by writing in the above the arrow. C 2 A. C 2 epoxide C. C 2 Cl C 2 B. D. Give the best reagent or set of for each transformation. a C b 3 C C=C2 C3 C C C3 C C c C C C3 d C C a. b. c. d. I 4,! Complete the following reactions: 1.B 3 TF , Pt, D 2 show correct stereochemsitry Cl 2 C 3, phase transfer catalyst 8

10 A d d i t i o n R e a c t i o n s - C o n d i t i o n s Give the reaction next to the arrow. Letter L was done for you: K. L. 2 A. B. C 2 C. J. C 2 D. plus C 2 & 2 I. G. E.. F. Cl Complete the following by taking the lettered compound from above then reacting on it using the specified reagent shown below then name each reaction: name the reaction NaN 2 C3 1st A. 2nd A. 2 S 4! pink handout RR 1st 2nd L. Zn(s) 1. 3 pink handout 2.Zn(s) 1st 2nd J st K. 2 hv LDA 1st 2nd 9

11 R e a c t i o n s Complete by filling in the missing, condition(s) and/or product(s) Cl K! ( C 2 )( )CC K! C C 2 C (E) alkene ot KMn 4 C 2 C C 2 C 2 K t-buk potassium t-butoxide 1.MCPBA specify stereochemistry C 2 1.g(Ac) 2, 2 2.NaB 4 2 S 4! Cl 2 Cl C 1.MCPBA 3 C 2. 3 C 2, + & 3 & Cl 10

12 S y n t h e s i s Starting from, give a reasonable synthesis the following: synthesize starting from synthesize starting from synthesize starting from Cl synthesize starting from starting from Cl synthesize 11

13 S A MP L E Q UIZ a. Give a stepwise mechanism for the following reaction. Your mechanism should show individual steps in the reaction that lead to all the products formed. Use curved arrows and indicate all formal charges. b Draw a representative potential energy curve that correctly shows your mechanism. Label important intermediates and transition states on your potential diagram. C C C C C 2 energy reaction time 2. Give the best reagent or set of for each transformation. C C C C 2 C a b c C d C=C2 C3 C C2 C2 C C C C C C a. b. c. d. I 4,! 12

14 3. Complete the following reaction and show correct stereochemistry where appropriate. reaction name reaction name show correct stereochemsitry cold KMn 4 - Pt, D 2 show correct stereochemsitry Cl 2, 2 C 3, phase transfer catalyst 4. Give the needed the formation of the products under the given. peroxyacetic acid 2, + (±)-2,3-pentanediol 2 hv 5. Starting with the compound on the left, show synthetic steps that lead up to the target molecule on the right. 13